Coquilles Saint Jacques Parisienne

• 6 shallots
• 2 egg yolks
• 1 bouquet garni
• 1 onion (finely chopped)
• 500 gr scallops washed
• 350 ml dry wine (white)
• 80 gr mushrooms (fresh)
• 60 ml cream (heavy)
• 55 gr butter
• 32 gr flour